CA1043649A - Tobacco-smoke filters - Google Patents
Tobacco-smoke filtersInfo
- Publication number
- CA1043649A CA1043649A CA273,681A CA273681A CA1043649A CA 1043649 A CA1043649 A CA 1043649A CA 273681 A CA273681 A CA 273681A CA 1043649 A CA1043649 A CA 1043649A
- Authority
- CA
- Canada
- Prior art keywords
- smoke
- filter element
- face
- groove
- element according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/04—Tobacco smoke filters characterised by their shape or structure
- A24D3/043—Tobacco smoke filters characterised by their shape or structure with ventilation means, e.g. air dilution
Abstract
ABSTRACT
A filter element for a smoking article, such as a cigarette, comprises a generally cylindrical body having at least one helical groove in its peripheral surface and closely wrapped in a material pervious to vapour-phase constituents of the smoke, whereby such constituents are removed by diffusion thereof through said material during passage of the smoke along the groove. The body may be wholly or in part of a filter material capable of removing particulate-phase constituents from the smoke during its passage through the element. Suitably the groove extends from the upstream end face of the body to a point short of the downstream end face, where it opens into a space separated from the downstream end by an ungrooved portion of smoke-filter material. One or more faces of the groove and/or said upstream end face may be partially or wholly sealed against penetration of smoke into the body.
A filter element for a smoking article, such as a cigarette, comprises a generally cylindrical body having at least one helical groove in its peripheral surface and closely wrapped in a material pervious to vapour-phase constituents of the smoke, whereby such constituents are removed by diffusion thereof through said material during passage of the smoke along the groove. The body may be wholly or in part of a filter material capable of removing particulate-phase constituents from the smoke during its passage through the element. Suitably the groove extends from the upstream end face of the body to a point short of the downstream end face, where it opens into a space separated from the downstream end by an ungrooved portion of smoke-filter material. One or more faces of the groove and/or said upstream end face may be partially or wholly sealed against penetration of smoke into the body.
Description
This invention concerns improvements relating to filters for smoking-articles, particularly but not exclusively tobacco-smoke filters for cigarettes. It seeks to provide a filter by which high ' reductions of smoke constituents of lower molecular weight, for example and particularly carbon monoxide, as well as reductions of particulate-phase constituents, that is heavier constituents such as tars, can be achieved by simple, practical, means.
According to the invention, a smoking-article filter element comprises a generally cylindrical body which has at least one helical groove in its peripheral surface and is closely wrapped in a material '~ pervious to vapour-phase constituents of the smoke, whereby vapour-phase constituents are removed by diffusion thereof through said t~ wrapping material during passage of the smoke along the groove or ; grooves. By the use of such a filter element, the delivery of smoke ~, constituents of lower molecular weight i~ ~ery materially reduced due to outward diffusion thereof from the groove or grooves through the wr8pping material, for example paper. At the ~ame time, the delivery ~' of heavier constituents is also substantially reduced due to the effeot,~ upon the combustion process, of inward penetration of air through the~wr8pping material into the groove or grooves.
''~ Adv~ntageously, the body is made wholly or in part of a filter material~oapable~of removing particulate-phase constituents from the `' ~ moke dùri~g 1ts~passage through the filter element. In this oase, removal of the heavier constituents may be increased by passage'of thé~smoke tbrough part of the body made of the filter material.
Removal of 1ighter constituents may also be en~pnced.
Preferably,~the~groove or grooves extend rrom the upstream end~face of~the~body to~a~point short of the downstream end face reof~ They~may~ terminate in or open at the downstream end thereof -30~ into~a spaoe~10ca~ed~in the body~short of its downstream end face, `for~ex~mple~an~nu1ar groove in the said body. ~Advantageously, the '?'~.`.''' ~ said spac~is then separated from the downstream end face of the ~ ' body by an ungrooved end portion, made oi smo~e-fi1ter D~teria1, oi : "
. ~.
. . . -10~ 9 the body. With this form of element, as the smoke pas~es along its length, filtration will occur in two main stages: Firstly, as the ~ -smoke passes along the helical groove or grooves, lighter smoke -constituents, for example carbon monoxide, will diffuse outwardly through the wrapping material, while air will penetrate inwardly.
Secondly, the smoke will then pass from the aforesaid space and through the said ungrooved portion, made for example of cellulose acetate or other thermoplastic filter material or of paper, by which particulate-phase constituents are removed.
me aforesaid body, prior to being grooved, may or may not be wrapped in known manner, but the external wrapping material already referred to is not grooved. The external wrapping material or, if a tipping material is also provided, the combination of external wrapping material and tipping material must be of such porosity that outward ~iffusion can take place from the groove or grooves into the atmosphere. In some cases, there may also be I dirfus1on into the body. Suitable porosity ranges for the said r external wra ing material or the combination of that material and tipping material, if used, are, broadly, between 500 and 15,000 cc/min/10cm2/10cm W.G.
One embodiment of the invention will now be described, by way~of exa~ple, with reference to the accompanying diagrammatic drawing, which shows part of a filter clgarette with some elements partly removed.
I ~
The cigarette comprises a rod of tobacco 1 and a filter 2.
The filter 2 comprises a generaIly cylindrical element 3, or plug , body, of cellulose acetate, which element 3 is closely wrapped in :: :
~; a porous paper wrap 4. The tobacoo rod 1 is wrapped in cigarette paper~5, and the~ rod 1 and~filter 2 are connected together by a 30~ porous;tipping~band 6. me latter band need t extend for the full le ~ of;the element 3 as illustrated or it may be omitted, in which case à short band serving simply to connect the wrapped rod 1 to the .. ~ ., .
; ~ wrap~ed filter element 3 may be providedO
,~, .
. .
~ - 2 -.~
1043~9 A square-section helical groove 7 extends at the peripheral surface of the element 3 from the tobacco-end end face 8 of the element, over a major portion of the length of the element, to an annular groove 9, that is a groove in a plane normal to the axis of he element. The remaining portion 10 of the element 3 is of un-grooved regular cylindrical form.
When the cigarette is smoked, tobacco smoke from the tobacco rod 1 passes (as indicated by arrows in the drawing) along the helical groove 7 into the groove 9, which acts as a smoke-distribution groove, and thence through the portion 10 of the filter element 3.
During smoking, as the smoke passes along the groove 7, smoke constituents of lower molecular weight, for example carbon monoxide, will diffuse outwardly through the wrap 4 and the tipping band 6, while air penetrates inwardly. As the smoke subsequently passes through the portion 10 of the element 3 particulate-phase constituents~
of the smoke, i.e. heavier constituents such as tars, are removed.
Generally, in this embodiment of the invention, the face 8 of the element 3 and the faces of the groove 7 will not be sealed, that is of reduced previousness to smoke. A small proportion of the smoke stream will pass into the element 3 upstream of the portion 10, this also resulting in removal of particulate-phase constituents and a small proportion of the constituents of lower molecular weight.
If the said faces are sealed at all, they should not be more than partially sealed.
Instead of the flat end face 8, the filter element 3 may have a conical end with the apex pointing upstream. In this case, the end may be at least partially sealed. Such conical shape and or ; ;
sealing may serve to guide the smoke into the helical groove.
~ More than one helical groove may be provided after the 1~ 30 fashion, say, of a two-start screw-thread.
Filter materials other than ~ellulose acetate, for example another thermoplastic filter material or paper, may be used for the ` element 30 Particulate carbon or other adsorbent material may be ..
,i, ~ .
.
, ...... . . . . . .
1 ~ 3~ ~.9 incorporated in the material of the filter element.
~ A grooved filter element such as the element 3 may be produced, o ~ for example, by the method described and claimed in the Specification ~ , of ~h~ co-pendin~ Appli¢atif~n ~o. of even date, that is by feeding a cylindrical rod of the filter material in a direction tranæverse to its length past a heated projecting member or members by which grooves are formed in the rod, which is meanwhile turned about its axis, under the effect of heat and pressure. For a helical groove, such as 7, the forming member will be located at an angle to the rod and no relative axial movement occurs between the rod and the forming member. An annular groove, such as 9, is formed by a ~econd forming member. If a partial or complete surface-sealing effect is required, the heating of the part or parts of the forming member producing the face or faces to be sealed may be made such as to bring the filter material locally to a temperature sufficient to produce superficial fusion thereof and partial or complete sealing at the said face or faces, as required.
Tests have been carried out which illustrate reductions of C0 and total particulate material (T.P.M.) which have been obtained.
For the purposes of the tests, a cylindrical filter element 20mm ~ ~ long was used having in its peripheral surface, over its whole `~ ~ length, a helical groove of square section, substantially as shown in~the~drawing, but without the end portion 10 and without the tipping band 6, the ob~ect being to illustrate the effects of the helical~groove 7 and porous wrap 4 alone. The groove had a width of~3mm and~a~ pitch of-6mm. The pitch angle was thus about 10.
The tests were divided into three groups:
GROUP I
The cylindrical elements, formed of cellulose acetate, were 30~ wrapp-d~in a number~or papers of different porosity values, some of which were naturally porous paper and other electrostatically perforated paper.
~, , .
1 ~Li3~-9 Tobacco smoke was dra~n through each wrapped element from a rod of tobacco smoked under standard conditions, i.e. one puff per minute of 35 cm3 volume and two seconds duration. A comparable cigarette, but having no filter, was smoked under the same conditions as a test control. me results of the Group I tests are shown in Table I. As for all Groups, porosities are in units of cm3/10 cm2 of air flow/ 100mm Water Gauge/minute:
Paper Porosity CO Reduction (%) T.P.M.Reduction (%) l by weight by weight 1,00020 39 Naturally porous 5,00046 56 1,20052 64 Electrostatically 3,00058 70 Perforated 10,QOO78 86 . .
Table I
GROUP II
The Group II tests were identical with the first two tests of Group I except that the tobacco-end faces 8 of the cellulose acetate elements were partially sealed by applying thereto a solution of cellulose acetate in acetone. me results of these tests are given in Table II.
._ Paper Porosity O Reduction (%) T.P.M.Reduction (%) by weight by weight l ( 1,000 21 42 Naturally porous ( 5,000 41 54 -.
Table II
. ~.
\ . . : ~ .
~- - ,, . - ,..... , . - . . . . . . .
.. ~. , , .. . . .- , ..
1C~3~;~9 GROUP III
In order to obtain results for elements having the end faces 8 and the faces of the helical grooves 7 totally impervious to tobacco smoke, tests were made corresponding to those of Group I but with elements formed of ~Perspex~ (Trade Mark). The results are given in Table III:
Paper Porosity C0 Reduction (%) T.P.M.Reduction (%) by weight by weight ~ 1,000 19 23 Naturally porous 5,000 39 38 ~ 1,200 35 56 Electrostatically ~
3,000 44 62 l Perforated l 10,000 65 66 ! Table III
As the results set out in the three tables show, the carbon monoxlde reductions increased as the porosity value of the paper !
inoreased. ~1ectrostatically perforated papers gave higher levels ~ 20 of carbon-monoxide reduction than did naturally porous papers.
i~ These observatlons also hold good in regard to the levels of reduction of total particulate matter.
Referring to Tables I and III, very good C0 and T.P.M.
~r`;~ reduotions were obtained with electrostatically perforated paper ~'~ having a poroslty value of 10,000. Even better C0 and T.P.M.
reductlons might result from using papers with yet higher porosity values, but the law of diminlshing returns would apply. Also at , ; ~ very hlgh poroslty values, it might be difficult or impossible to ; maintain the~bwl7~ ~g of a ciga~ette.
30~ ; Gomparing the~results of Table II with those of Table I, it can ; be~seen that the partial sealing of the tobacco-end faces of the cellulose acetate elements had a minimal effect upon the C0 and T.P~M. reductions. However, a comparison of the results of Table III wlth th~ of Table I shows, especially in regard to the electro-., ~' .
l 6 .~
11k~3~ 9 statically perforated papers, that total sealing of the end faces 8 .
and grooves of the elements led to significantly lower reductions of CO and T.P.M.
.~, ~ ' ' : - 7 -
According to the invention, a smoking-article filter element comprises a generally cylindrical body which has at least one helical groove in its peripheral surface and is closely wrapped in a material '~ pervious to vapour-phase constituents of the smoke, whereby vapour-phase constituents are removed by diffusion thereof through said t~ wrapping material during passage of the smoke along the groove or ; grooves. By the use of such a filter element, the delivery of smoke ~, constituents of lower molecular weight i~ ~ery materially reduced due to outward diffusion thereof from the groove or grooves through the wr8pping material, for example paper. At the ~ame time, the delivery ~' of heavier constituents is also substantially reduced due to the effeot,~ upon the combustion process, of inward penetration of air through the~wr8pping material into the groove or grooves.
''~ Adv~ntageously, the body is made wholly or in part of a filter material~oapable~of removing particulate-phase constituents from the `' ~ moke dùri~g 1ts~passage through the filter element. In this oase, removal of the heavier constituents may be increased by passage'of thé~smoke tbrough part of the body made of the filter material.
Removal of 1ighter constituents may also be en~pnced.
Preferably,~the~groove or grooves extend rrom the upstream end~face of~the~body to~a~point short of the downstream end face reof~ They~may~ terminate in or open at the downstream end thereof -30~ into~a spaoe~10ca~ed~in the body~short of its downstream end face, `for~ex~mple~an~nu1ar groove in the said body. ~Advantageously, the '?'~.`.''' ~ said spac~is then separated from the downstream end face of the ~ ' body by an ungrooved end portion, made oi smo~e-fi1ter D~teria1, oi : "
. ~.
. . . -10~ 9 the body. With this form of element, as the smoke pas~es along its length, filtration will occur in two main stages: Firstly, as the ~ -smoke passes along the helical groove or grooves, lighter smoke -constituents, for example carbon monoxide, will diffuse outwardly through the wrapping material, while air will penetrate inwardly.
Secondly, the smoke will then pass from the aforesaid space and through the said ungrooved portion, made for example of cellulose acetate or other thermoplastic filter material or of paper, by which particulate-phase constituents are removed.
me aforesaid body, prior to being grooved, may or may not be wrapped in known manner, but the external wrapping material already referred to is not grooved. The external wrapping material or, if a tipping material is also provided, the combination of external wrapping material and tipping material must be of such porosity that outward ~iffusion can take place from the groove or grooves into the atmosphere. In some cases, there may also be I dirfus1on into the body. Suitable porosity ranges for the said r external wra ing material or the combination of that material and tipping material, if used, are, broadly, between 500 and 15,000 cc/min/10cm2/10cm W.G.
One embodiment of the invention will now be described, by way~of exa~ple, with reference to the accompanying diagrammatic drawing, which shows part of a filter clgarette with some elements partly removed.
I ~
The cigarette comprises a rod of tobacco 1 and a filter 2.
The filter 2 comprises a generaIly cylindrical element 3, or plug , body, of cellulose acetate, which element 3 is closely wrapped in :: :
~; a porous paper wrap 4. The tobacoo rod 1 is wrapped in cigarette paper~5, and the~ rod 1 and~filter 2 are connected together by a 30~ porous;tipping~band 6. me latter band need t extend for the full le ~ of;the element 3 as illustrated or it may be omitted, in which case à short band serving simply to connect the wrapped rod 1 to the .. ~ ., .
; ~ wrap~ed filter element 3 may be providedO
,~, .
. .
~ - 2 -.~
1043~9 A square-section helical groove 7 extends at the peripheral surface of the element 3 from the tobacco-end end face 8 of the element, over a major portion of the length of the element, to an annular groove 9, that is a groove in a plane normal to the axis of he element. The remaining portion 10 of the element 3 is of un-grooved regular cylindrical form.
When the cigarette is smoked, tobacco smoke from the tobacco rod 1 passes (as indicated by arrows in the drawing) along the helical groove 7 into the groove 9, which acts as a smoke-distribution groove, and thence through the portion 10 of the filter element 3.
During smoking, as the smoke passes along the groove 7, smoke constituents of lower molecular weight, for example carbon monoxide, will diffuse outwardly through the wrap 4 and the tipping band 6, while air penetrates inwardly. As the smoke subsequently passes through the portion 10 of the element 3 particulate-phase constituents~
of the smoke, i.e. heavier constituents such as tars, are removed.
Generally, in this embodiment of the invention, the face 8 of the element 3 and the faces of the groove 7 will not be sealed, that is of reduced previousness to smoke. A small proportion of the smoke stream will pass into the element 3 upstream of the portion 10, this also resulting in removal of particulate-phase constituents and a small proportion of the constituents of lower molecular weight.
If the said faces are sealed at all, they should not be more than partially sealed.
Instead of the flat end face 8, the filter element 3 may have a conical end with the apex pointing upstream. In this case, the end may be at least partially sealed. Such conical shape and or ; ;
sealing may serve to guide the smoke into the helical groove.
~ More than one helical groove may be provided after the 1~ 30 fashion, say, of a two-start screw-thread.
Filter materials other than ~ellulose acetate, for example another thermoplastic filter material or paper, may be used for the ` element 30 Particulate carbon or other adsorbent material may be ..
,i, ~ .
.
, ...... . . . . . .
1 ~ 3~ ~.9 incorporated in the material of the filter element.
~ A grooved filter element such as the element 3 may be produced, o ~ for example, by the method described and claimed in the Specification ~ , of ~h~ co-pendin~ Appli¢atif~n ~o. of even date, that is by feeding a cylindrical rod of the filter material in a direction tranæverse to its length past a heated projecting member or members by which grooves are formed in the rod, which is meanwhile turned about its axis, under the effect of heat and pressure. For a helical groove, such as 7, the forming member will be located at an angle to the rod and no relative axial movement occurs between the rod and the forming member. An annular groove, such as 9, is formed by a ~econd forming member. If a partial or complete surface-sealing effect is required, the heating of the part or parts of the forming member producing the face or faces to be sealed may be made such as to bring the filter material locally to a temperature sufficient to produce superficial fusion thereof and partial or complete sealing at the said face or faces, as required.
Tests have been carried out which illustrate reductions of C0 and total particulate material (T.P.M.) which have been obtained.
For the purposes of the tests, a cylindrical filter element 20mm ~ ~ long was used having in its peripheral surface, over its whole `~ ~ length, a helical groove of square section, substantially as shown in~the~drawing, but without the end portion 10 and without the tipping band 6, the ob~ect being to illustrate the effects of the helical~groove 7 and porous wrap 4 alone. The groove had a width of~3mm and~a~ pitch of-6mm. The pitch angle was thus about 10.
The tests were divided into three groups:
GROUP I
The cylindrical elements, formed of cellulose acetate, were 30~ wrapp-d~in a number~or papers of different porosity values, some of which were naturally porous paper and other electrostatically perforated paper.
~, , .
1 ~Li3~-9 Tobacco smoke was dra~n through each wrapped element from a rod of tobacco smoked under standard conditions, i.e. one puff per minute of 35 cm3 volume and two seconds duration. A comparable cigarette, but having no filter, was smoked under the same conditions as a test control. me results of the Group I tests are shown in Table I. As for all Groups, porosities are in units of cm3/10 cm2 of air flow/ 100mm Water Gauge/minute:
Paper Porosity CO Reduction (%) T.P.M.Reduction (%) l by weight by weight 1,00020 39 Naturally porous 5,00046 56 1,20052 64 Electrostatically 3,00058 70 Perforated 10,QOO78 86 . .
Table I
GROUP II
The Group II tests were identical with the first two tests of Group I except that the tobacco-end faces 8 of the cellulose acetate elements were partially sealed by applying thereto a solution of cellulose acetate in acetone. me results of these tests are given in Table II.
._ Paper Porosity O Reduction (%) T.P.M.Reduction (%) by weight by weight l ( 1,000 21 42 Naturally porous ( 5,000 41 54 -.
Table II
. ~.
\ . . : ~ .
~- - ,, . - ,..... , . - . . . . . . .
.. ~. , , .. . . .- , ..
1C~3~;~9 GROUP III
In order to obtain results for elements having the end faces 8 and the faces of the helical grooves 7 totally impervious to tobacco smoke, tests were made corresponding to those of Group I but with elements formed of ~Perspex~ (Trade Mark). The results are given in Table III:
Paper Porosity C0 Reduction (%) T.P.M.Reduction (%) by weight by weight ~ 1,000 19 23 Naturally porous 5,000 39 38 ~ 1,200 35 56 Electrostatically ~
3,000 44 62 l Perforated l 10,000 65 66 ! Table III
As the results set out in the three tables show, the carbon monoxlde reductions increased as the porosity value of the paper !
inoreased. ~1ectrostatically perforated papers gave higher levels ~ 20 of carbon-monoxide reduction than did naturally porous papers.
i~ These observatlons also hold good in regard to the levels of reduction of total particulate matter.
Referring to Tables I and III, very good C0 and T.P.M.
~r`;~ reduotions were obtained with electrostatically perforated paper ~'~ having a poroslty value of 10,000. Even better C0 and T.P.M.
reductlons might result from using papers with yet higher porosity values, but the law of diminlshing returns would apply. Also at , ; ~ very hlgh poroslty values, it might be difficult or impossible to ; maintain the~bwl7~ ~g of a ciga~ette.
30~ ; Gomparing the~results of Table II with those of Table I, it can ; be~seen that the partial sealing of the tobacco-end faces of the cellulose acetate elements had a minimal effect upon the C0 and T.P~M. reductions. However, a comparison of the results of Table III wlth th~ of Table I shows, especially in regard to the electro-., ~' .
l 6 .~
11k~3~ 9 statically perforated papers, that total sealing of the end faces 8 .
and grooves of the elements led to significantly lower reductions of CO and T.P.M.
.~, ~ ' ' : - 7 -
Claims (9)
1. A smoking-article filter element comprising a generally cylindrical body which has at least one helical groove in its peripheral surface and is closely wrapped in a material pervious to vapour-phase constituents of the smoke, whereby vapour-phase constituents are removed by diffusion thereof through said wrapping material during passage of the smoke along the said helical groove.
2. A filter element according to claim 1, wherein the body is made at least in part of a filter material capable of removing particulate-phase constituents from the smoke during its passage through the said element.
3. A filter element according to claim 1, wherein the said helical groove extends from the upstream end face of the body to a point short of the downstream end face thereof.
4. A filter element according to claim 1, wherein the said helical groove opens at the downstream end thereof into a space located in the body short of its downstream end face.
5. A filter element according to claim 4, wherein the said space is a peripheral annular groove formed in the body.
6. A filter element according to claim 4, wherein the said space is separated from the downstream end of the body by an ungrooved end portion, made of smoke-filter material, of the body.
7. A filter element according to claim 1, wherein at least one face bounding the said helical groove in the body is at least partially sealed against penetration of smoke from the groove into the body.
8. A filter element according to claim 1, wherein the upstream end face of the body is at least partially sealed against the penetration of smoke into the body.
9. A smoking article incorporating a filter element according to claim 1.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB10776/76A GB1508084A (en) | 1976-03-17 | 1976-03-17 | Tobacco-smoke filters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1043649A true CA1043649A (en) | 1978-12-05 |
Family
ID=9974059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,681A Expired CA1043649A (en) | 1976-03-17 | 1977-03-10 | Tobacco-smoke filters |
Country Status (13)
| Country | Link |
|---|---|
| US (1) | US4135523A (en) |
| AU (1) | AU504334B2 (en) |
| BE (1) | BE852574A (en) |
| BR (1) | BR7701600A (en) |
| CA (1) | CA1043649A (en) |
| CH (1) | CH616569A5 (en) |
| DE (1) | DE2711742A1 (en) |
| DK (1) | DK152003C (en) |
| FI (1) | FI61616C (en) |
| GB (1) | GB1508084A (en) |
| MX (1) | MX144582A (en) |
| NL (1) | NL186997C (en) |
| ZA (1) | ZA771364B (en) |
Families Citing this family (46)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1096737A (en) * | 1977-03-14 | 1981-03-03 | Jan Van Tilburg | Smoke filters |
| US4219030A (en) * | 1977-08-19 | 1980-08-26 | Liggett Group Inc. | Aeration groove filter |
| US4232574A (en) * | 1977-08-19 | 1980-11-11 | Liggett Group Inc. | Apparatus and method for providing a cigarette filter with an aeration groove |
| US4369796A (en) * | 1977-08-19 | 1983-01-25 | Liggett Group Inc. | Method and apparatus for forming an air dilution filter |
| US4253508A (en) * | 1979-01-19 | 1981-03-03 | Bodai Industries, Inc. | Selective filtering of tobacco smoke by enhanced filtration efficiency |
| US4256122A (en) * | 1979-04-11 | 1981-03-17 | Brown & Williamson Tobacco Corporation | Cigarette filter |
| ZA804948B (en) * | 1979-08-28 | 1981-06-24 | British American Tobacco Co | Smoke filtration |
| CA1156533A (en) * | 1980-05-01 | 1983-11-08 | Henry G. Horsewell | Smoking articles |
| DE3048905A1 (en) * | 1980-12-23 | 1982-07-22 | B.A.T. Cigaretten-Fabriken Gmbh, 2000 Hamburg | Cigarette filter with impermeable wrapping - has troughs in wrapping running continuously from end to end |
| US4498488A (en) * | 1981-03-12 | 1985-02-12 | Brown & Williamson Tobacco Corporation | Cigarette filter |
| US4616664A (en) * | 1981-03-17 | 1986-10-14 | American Brands, Inc. | Tobacco product |
| US4637409A (en) * | 1981-05-07 | 1987-01-20 | American Filtrona Corporation | Tobacco smoke filter and method and apparatus for making same |
| IL66401A (en) * | 1981-08-03 | 1985-07-31 | Brown & Williamson Tobacco | Filter cigarette |
| US4492238A (en) | 1981-09-30 | 1985-01-08 | Philip Morris Incorporated | Method and apparatus for production of smoke filter components |
| GB2116824B (en) * | 1982-02-02 | 1985-07-24 | Brown & Williamson Tobacco | Improvements relating to smoke filters |
| US4406294A (en) * | 1982-02-16 | 1983-09-27 | Brown & Williamson Tobacco Corporation | Cigarette filter |
| US4535793A (en) * | 1982-08-18 | 1985-08-20 | Brown & Williamson Tobacco Corporation | Smoking article filters |
| US4476882A (en) * | 1983-02-07 | 1984-10-16 | Brown & Williamson Tobacco Corporation | Tobacco smoke filters |
| US4527572A (en) * | 1983-02-07 | 1985-07-09 | Brown & Williamson Tobacco Corporation | Tobacco smoke filters |
| US4557281A (en) * | 1983-12-05 | 1985-12-10 | Brown & Williamson Tobacco Corporation | Filtered cigarette |
| DE3444991A1 (en) * | 1984-12-10 | 1986-06-19 | Hans Balsthal Elstner | FILTERS FOR SMOKING GOODS AND SMOKING DEVICES |
| GB8713904D0 (en) * | 1987-06-15 | 1987-07-22 | Tabac Fab Reunies Sa | Filter for smoking articles |
| CN1748591A (en) * | 2005-11-07 | 2006-03-22 | 夏侯晓雷 | Filter tip |
| US7987856B2 (en) | 2005-12-29 | 2011-08-02 | Philip Morris Usa Inc. | Smoking article with bypass channel |
| US8240315B2 (en) * | 2005-12-29 | 2012-08-14 | Philip Morris Usa Inc. | Smoking article with improved delivery profile |
| MX2008012396A (en) * | 2006-03-28 | 2009-02-11 | Philip Morris Prod | Smoking article with a restrictor. |
| US8353298B2 (en) * | 2006-07-12 | 2013-01-15 | Philip Morris Usa Inc. | Smoking article with impaction filter segment |
| US7874296B1 (en) * | 2006-07-26 | 2011-01-25 | Mohammad Said Saidi | Cigarette gas filter |
| US8424539B2 (en) * | 2006-08-08 | 2013-04-23 | Philip Morris Usa Inc. | Smoking article with single piece restrictor and chamber |
| GB0624321D0 (en) * | 2006-12-05 | 2007-01-17 | British American Tobacco Co | Tobacco smoke filter and methods of making the same |
| US8235056B2 (en) * | 2006-12-29 | 2012-08-07 | Philip Morris Usa Inc. | Smoking article with concentric hollow core in tobacco rod and capsule containing flavorant and aerosol forming agents in the filter system |
| TW200911138A (en) * | 2007-03-09 | 2009-03-16 | Philip Morris Prod | Smoking articles with restrictor and aerosol former |
| TW200900014A (en) * | 2007-03-09 | 2009-01-01 | Philip Morris Prod | Smoking article filter with annular restrictor and downstream ventilation |
| TW200911141A (en) * | 2007-03-09 | 2009-03-16 | Philip Morris Prod | Super recessed filter cigarette restrictor |
| US20080216850A1 (en) * | 2007-03-09 | 2008-09-11 | Philip Morris Usa Inc. | Restrictor attachment for unfiltered smoking article |
| GB0809865D0 (en) * | 2008-05-30 | 2008-07-09 | British American Tobacco Co | Filter for a smoking article |
| EP2343996A1 (en) * | 2008-10-31 | 2011-07-20 | R.J. Reynolds Tobacco Company | Tipping materials for filtered cigarettes |
| US20100108084A1 (en) * | 2008-10-31 | 2010-05-06 | Norman Alan B | Filtered cigarette with diffuse tipping material |
| US20100108081A1 (en) * | 2008-10-31 | 2010-05-06 | Leigh Ann Blevins Joyce | Filtered cigarette with flavored tipping material |
| US20110083687A1 (en) * | 2009-10-09 | 2011-04-14 | Philip Morris Usa Inc. | Cigarette filter to reduce smoke deliveries in later puffs |
| AR080556A1 (en) | 2009-10-09 | 2012-04-18 | Philip Morris Prod | FILTER DESIGN TO IMPROVE THE SENSORY PROFILE OF ARTICLES FOR SMOKING WITH CARBON FILTER NOZZLE |
| US8424540B2 (en) * | 2009-10-09 | 2013-04-23 | Philip Morris Usa Inc. | Smoking article with valved restrictor |
| US8905037B2 (en) * | 2009-10-15 | 2014-12-09 | Philip Morris Inc. | Enhanced subjective activated carbon cigarette |
| US9138016B2 (en) | 2010-03-26 | 2015-09-22 | Philip Morris Usa Inc. | Smoking articles with significantly reduced gas vapor phase smoking constituents |
| GR1007749B (en) * | 2011-05-04 | 2012-11-02 | Αντωνιος Μαστροκαλος | Filter for cigarettes |
| WO2015009863A1 (en) * | 2013-07-19 | 2015-01-22 | Altria Client Services Inc. | Electronic smoking article |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1349992A (en) * | 1962-11-29 | 1964-01-24 | Self-cooling cigarette | |
| US3336928A (en) * | 1964-05-07 | 1967-08-22 | James W Haley | Smoking article |
| US3490461A (en) * | 1967-04-20 | 1970-01-20 | Philip Morris Inc | Cigarette ventilation |
| DE2302677A1 (en) * | 1972-04-12 | 1973-10-18 | Eastman Kodak Co | TOBACCO SMOKE FILTER ELEMENT AND METHOD OF ITS MANUFACTURING |
| US3964493A (en) * | 1972-09-07 | 1976-06-22 | Baker-Alpha Corporation | Cigarette filter |
| SE381167B (en) * | 1974-03-13 | 1975-12-01 | Svenska Tobaks Ab | FILTER FOR TOBACCO SMOKE |
-
1976
- 1976-03-17 GB GB10776/76A patent/GB1508084A/en not_active Expired
-
1977
- 1977-03-08 FI FI770731A patent/FI61616C/en active
- 1977-03-08 ZA ZA00771364A patent/ZA771364B/en unknown
- 1977-03-10 AU AU23134/77A patent/AU504334B2/en not_active Expired
- 1977-03-10 CA CA273,681A patent/CA1043649A/en not_active Expired
- 1977-03-10 NL NLAANVRAGE7702584,A patent/NL186997C/en active Search and Examination
- 1977-03-11 US US05/776,774 patent/US4135523A/en not_active Expired - Lifetime
- 1977-03-15 MX MX168376A patent/MX144582A/en unknown
- 1977-03-16 BR BR7701600A patent/BR7701600A/en unknown
- 1977-03-16 DK DK114877A patent/DK152003C/en not_active IP Right Cessation
- 1977-03-17 DE DE19772711742 patent/DE2711742A1/en active Granted
- 1977-03-17 BE BE175874A patent/BE852574A/en not_active IP Right Cessation
- 1977-03-17 CH CH335077A patent/CH616569A5/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| BE852574A (en) | 1977-07-18 |
| ZA771364B (en) | 1978-01-25 |
| NL7702584A (en) | 1977-09-20 |
| AU2313477A (en) | 1978-09-14 |
| FI61616B (en) | 1982-05-31 |
| DK152003C (en) | 1988-07-11 |
| BR7701600A (en) | 1978-05-09 |
| MX144582A (en) | 1981-10-28 |
| US4135523A (en) | 1979-01-23 |
| DK114877A (en) | 1977-09-18 |
| DE2711742C2 (en) | 1988-02-18 |
| FI770731A (en) | 1977-09-18 |
| FI61616C (en) | 1982-09-10 |
| NL186997C (en) | 1991-05-01 |
| DK152003B (en) | 1988-01-25 |
| AU504334B2 (en) | 1979-10-11 |
| GB1508084A (en) | 1978-04-19 |
| DE2711742A1 (en) | 1977-09-22 |
| CH616569A5 (en) | 1980-04-15 |
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